1. Field of the Invention
The present invention relates to a stirring container which stirs a liquid held therein by sound wave contactlessly and to analyzer which uses this stirring container.
2. Description of the Related Art
Conventionally, an analyzer is known in which ultrasonic waves are radiated to a reaction container from the outside and a sound flow is generated in the liquid sample which the reaction container holds and the liquid sample is stirred and mixed contactlessly, in order to downsize a reaction container and avoid contamination of analytes (see German Patent No. 10325307 and Patent No. 3168886).
In recent years, calls for trace amount of sample and trace amount of reagent have been intensified, and further miniaturization of reaction containers for liquids of several μL order has been still more required. When the container volume is reduced in order to meet these requests, there are cases in which portions where the liquid stirring cannot be conducted occur. When a portion where the liquid stirring cannot be conducted occurs, the ratio of an actual sample to a reagent held in the container and the ratio of the sample and the reagent to cause chemical reactions differ significantly, and as a result, it becomes difficult to perform accurate analysis.
In addition, when ultrasonic waves of tens to hundreds of MHz or higher frequency are used to carry out contactless stirring for trace amount of liquid, the flow generated in the liquid is predominantly generated by sound flows. Consequently, when ultrasonic waves are used, sufficient stirring with the liquid of other portions cannot be expected once a stagnant portion where sound flow cannot penetrate is generated. When sufficient stirring cannot be conducted, for example, part of reagent remains unstirred with the analyte, and accurate measurement of the analyte cannot be conducted.
As described above, in a reaction container of analyzer that handles, particularly, liquids of tens to a few μL or less as objects to be stirred, it becomes important to suppress generation of this kind of stagnant portion or hold down the size of the stagnant portion generated.